The present invention, in some embodiments thereof, relates to thermal images and, more particularly, but not exclusively, to the analysis of thermal images by determining a thermal signature within the images.
The use of imaging in diagnostic medicine dates back to the early 1900s. Presently there are numerous different imaging modalities at the disposal of a physician allowing imaging of hard and soft tissues and characterization of both normal and pathological tissues.
Infra red imaging is utilized for characterizing a thermally distinguishable site in a human body for the purposes of identifying inflammation. Infrared cameras produce two-dimensional images known as thermographic images. A thermographic image is typically obtained by receiving from the body of the subject radiation at any one of several infrared wavelength ranges and analyzing the radiation to provide a two-dimensional temperature map of the surface. The thermographic image can be in the form of either or both of a visual image and corresponding temperature data. The output from infrared cameras used for infrared thermography typically provides an image comprising a plurality of pixel data points, each pixel providing temperature information which is visually displayed, using a color code or grayscale code. The temperature information can be further processed by computer software to generate for example, mean temperature for the image, or a discrete area of the image, by averaging temperature data associated with all the pixels or a sub-collection thereof.
Based on the thermographic image, a physician diagnoses the site, and determines, for example, whether or not the site includes an inflammation while relying heavily on experience and intuition.
U.S. Pat. No. 7,072,504 discloses an approach which utilizes two infrared cameras (left and right) in combination with two visible light cameras (left and right). The infrared cameras are used to provide a three-dimensional thermographic image and the visible light cameras are used to provide a three-dimensional visible light image. The three-dimensional thermographic and three-dimensional visible light images are displayed to the user in an overlapping manner.
International Patent Publication No. 2006/003658, the contents of which are hereby incorporated by reference, discloses a system which includes non-thermographic image data acquisition functionality and thermographic image data acquisition functionality. The non-thermographic image data acquisition functionality acquires non-thermographic image data, and the thermographic image data acquisition functionality acquires thermographic image data.
U.S. Pat. No. 7,292,719, the contents of which are hereby incorporated by reference discloses a system for determining presence or absence of one or more thermally distinguishable objects in a living body. A combined image generator configured combines non-thermographic three-dimensional data of a three-dimensional tissue region in the living body with thermographic two-dimensional data of the tissue region so as to generate three-dimensional temperature data associated with the three-dimensional tissue region.
Also of interest is U.S. Pat. No. 6,442,419 disclosing a scanning system including an infrared detecting mechanism which performs a 360° data extraction from an object, and a signal decoding mechanism, which receives electrical signal from the infrared detecting mechanism and integrates the signal into data of a three-dimensional profile curved surface and a corresponding temperature distribution of the object.
Additional background art includes U.S. Pat. No. 6,850,862 which discloses the generation of three-dimensional maps of temperature distribution, and U.S. Pat. No. 5,961,466 which discloses detection of breast cancer from a rapid time series of infrared images which is analyzed to detect changes in the distribution of thermoregulatory frequencies over different areas of the skin.